GLASS-FIBRE REINFORCED COMPOSITES: THE EFFECT OF FIBRE LOADING AND ORIENTATION ON TENSILE AND IMPACT STRENGTH

The primary objective of this research work is to analyse the effect of fibre loading and orientation on the tensile and impact strength of the polymeric composite materials. Fibre reinforced composite materials have been reported to have attracted many applications in view of its low weight and superior strength when compared with the metal matrix composite. While researches have established the weight reduction of fibre reinforced polymer material, few works have reported the impact of orientation on the manufacturing of polymer composite. In this study, series of experimental works were done to demonstrate the manufacturing of glass-fibre reinforced epoxy resin with special attention on the influence of oriented reinforced composite material. The composites were manufactured using hand-lay technique with three different fibre loadings (10, 20, and 30 wt. %) and at two different fibre orientations (30o and 60o). Key of the finding drawn from this research form the basis of discussion and, composite with 60o fibre orientation showed better tensile strength when compared with the neat resin and other oriented (G10E30) fibre reinforced composite. Similar observations were also noticed on the impact strength of these composites which signify the improved mechanical properties of oriented reinforced composite materials. http://dx.doi.org/10.4314/njt.v36i3.1

Investigating water absorption and thickness swelling tendencies of polymeric composite materials for external wall application in refrigerated vehicles

Replacing external metallic wall of refrigerated vehicles has been on the front burner in many published works as weight of the metallic insulated panel continues to pose a challenge on refrigeration unit and environment. As a follow - up to this problem statement, five (5) composite materials were fabricated as replacement options for metallic external sheet for refrigerated vehicles. The key study of this paper is to investigate the moisture absorption and thickness swelling tendencies of these composite specimens as these properties determine the suitability of these materials for refrigerated wall. Part of the methodology adopted in the manufacturing of these composites were based on fibre loading and orientation in the composite panel. Key findings from this experiment shows that the absorption behaviour of composites at 30 oand 60o was consistent until 60 hours duration of immersion before a significant disparity was observed. In addition, G30E (30% reinforced glass fibre in the epoxy composite) was more resilient to moisture attack as a result of enhanced fiber content. The implication of the study is that G30E reinforced composite material could be adopted as external wall of food transport s ystem because of its lower thickness swelling and water absorption properties. Keywords : Composite materials, refrigerated vehicle, orientation, water absorption, thickness swelling

A Review on Application of Natural fibre in Structural Reinforcement: Challenges of Properties Adaptation

The foray of natural fibre reinforced composite in structural application is not new and researchers are currently considering different approaches of maximizing its performance. In many published works, natural fibres have enjoyed reasonable patronage in cooling applications and in cementitious structural materials. The moisture affinity of these fibres is another challenge that have dominated literature for ages. Moreover, modification of natural fibre in structural application is a herculean tasks that have not been established in many published works. In this work, properties and characteristics variation of natural fibre in structural reinforcement are discussed. Substantial part of this work is also dedicated to main properties inherent in natural fibre inimical to structural applications. It is expected that this work will assist researchers to formulate new compatible matrix materials suitable for further research works

Characterization and morphological properties of glass fiber reinforced epoxy composites fabricated under varying degrees of hand lay-up techniques

In this paper, attempts were made to study the progression of fibre-matrix adhesion of five composite specimens taking into consideration the hand lay-up method of composite formation. The ampreg 21 epoxy resin was used as the matrix for the glass fibre-epoxy resin formation. E- Glass fibre was used as matrix reinforcement. The morphology and the XRD of these composites were examined. Key of the findings from the morphological analysis of these composites showed that the fractured surface of the samples depicted better adhesion between the matrix and the fibres. The micrographs and EDS of the composite specimens also showed the retention of elemental composition of the glass fibre which is in line with other published works. The XRD results of these composites indicated a peak at Bragg’s angle 2θ=20.6o, affirming the remnant crystalline silica in the composite. Hence, these composites are projected to possess better dimensional stability adaptable for high performance structural applications.Keywords: composite, interfacial adhesion, morphology, reinforcing fibr

Comparative study and experimental analysis of pellets from biomass sawdust and rice husk

Sawdust and rice husk are available in abundance and indigenous in Nigeria but have not been exploited because they cannot be used directly in combustion processes due to their loose form unless by pelleting or briquetting. This experimental study assesses the potential of pellets from sawdust (SD) and rice husk (RH). Pallet samples collected from mills were thereafter optimized in ratios (i.e. 90%RH:10%SD, 80%RH:20%SD, 70RH:30SD, 60%RH:40%SD, 50%RH:50%SD, 100%RH and 100%SD) using mixing ratio optimization model. Seven samples were produced using a manual screw press machine and were subsequently categorized in terms of calorific value (CV), proximate and ultimate analyses using the ASTM standards. Results showed that the 100%RH pellets have higher CV of 31,026.3kJ/kg and the 100%SD a value of 26,088.3kJ/kg while the optimized pellets range from 25,867.39kJ/kg to 27,063.60kJ/kg. The CV decreases with increasing ash content of the pellets. It was also observed from the proximate analysis that the 100%RH has low percentages of moisture content, volatile matter and ash content compared to others. The optimized pellets showed that SD has the tendency to reduce the sulfur content in RH; hence, a promising alternative source of energy to the conventional fossil fuel

Influence of Gender on Rehabilitation and Reintegration of Recidivists: A Study of Female Inmates in Women’s Prisons in Selected Counties in Western Kenya

Women were nearly never mentioned in the history of criminal justice literature, while recidivism is one of the most fundamental concepts in the field. The high rate of female recidivism having resulted in an increasing number of people being jailed and then discharged  back into society, and the high risk of re-arrest, re-incarceration has become a top priority for governments, sociologists, the general public and those included in  correctional facilities. The research took place at three Western Kenya women's prisons: Kakamega Women's Prison, Bungoma Women's Prison, and Busia Women's Prison. The study's overall goal was to look into the influence of gender on female recidivists' rehabilitation and reintegration. The research was based on the following precise goal; to determine the patterns of recidivism among female prisoners in selected counties in western Kenya prisons. The study used a descriptive research approach and was based on gendered route theory and relational theory. Repeat offenders from the respective jail facilities made up the research population. To acquire the desired representation from the study population, purposive selection was performed. For this study, 150 female respondents were chosen from a target population of 240 recidivists. Questionnaires and guidelines for Key Informant Interviews were utilized to collect data. The quantitative data was analyzed using SPSS version 20.0 for windows, and the qualitative data were analyzed thematically. The study emphasizes the importance of introducing alternative rehabilitation approaches such as vocational training for female recidivists having manufacturing, processing, and farming technical talents and abilities. The study provides useful information and identifies a knowledge gap that the Kenyan prisons department and stakeholders would make use of to enhance legislation and rehabilitation techniques for female inmates. Females had a greater rate of recidivism, according to the study. The survey also discovered that the available rehabilitation programs don't really match the demands of the inmates. In addition, failure by the society to accept the female ex-convicts back into the community and to offer  them new opportunities for employment may result in further recidivism. Keywords: Gender, Rehabilitation, Reintegration, Recidivists, Female inmates DOI: 10.7176/PPAR/11-8-05 Publication date:October 31st 202

PRATIQUE DE LAVASECTOMIE SANS BISTOURIAU TOGO : L’EXPERIENCE DE LA CLINIQUE PRINCIPALE DE L’ASSOCIATION TOGOLAISE POUR LE BIEN- ETRE FAMILIAL (ATBEF)

Vasectomy is a surgical procedure that involves isolating and cut or coagulate the vas deferens. It represents 1.9% of modern contraceptive methods in the world. Fear of surgery, especially the fear of the pain of the incision and decreased libido, are some reasons to its low acceptance by men. The NSV, unlike conventional vasectomy, requires no incision or sutures and causes less pain. Objective: To describe the epidemiological characteristics and the prognostic of the no scalpel vasectomy in Togo. Methods: It was a prospective and descriptive study conducted at the Principal Clinic of ATBEF from May 1st, 2012 to April 30, 2013. It covered all cases of vasectomy. The variables analyzed using SPSS software were as follows: socio-demographic data, the motivations of patients, duration and complications of no-scalpel vasectomy. Results: The frequency of this vasectomy was 0,27%. The average age of patients was 41,7 years. The average number of children per couple was 4,7. The main motivation was sufficient number of children (72%) in the couple. The average operative time was 30 minutes. Vasectomy failed in 1 case (2%). Nine (9) cases of pain (scrotal and penile) and 2 cases of scrotal hematoma were the postoperative complications (22%). Conclusion: No scapel vasectomy is a simple practice accepted by the population. His prevalence is low but it can be improved by raising awareness

Application of the Dempster-Shafer Theory to the Classification of Pixels from Aster Satellite Images and Spectral Indices

In this paper, it is proposed to apply the Dempster-Shafer Theory (DST) or the theory of evidence to map vegetation, aquatic and mineral surfaces with a view to detecting potential areas of observation of outcrops of geological formations (rocks, breastplates, regolith, etc.). The proposed approach consists in aggregating information by using the DST. From pretreated Aster satellite images (geo-referencing, geometric correction and resampling at 15 m), newchannels were produced by determining the spectral indices NDVI, MNDWI and NDBaI. Then, the DST formalism was modeled and generated under the MATLAB software, an image segmented into six classes including three absolute classes (E,V,M) and three classes of confusion ({E,V}, {M,V}, {E,M}). The control on the land, based on geographic coordinates of pixels of different classes on said image, has made it possible to make a concordant interpretation thereof. Our contribution lies in taking into account imperfections (inaccuracies and uncertainties) related to source information by using mass functions based on a simple support model (two focal elements: the discernment framework and the potential set of belonging of the pixel to be classified) with a normal law for the good management of these